Why are there no frozen weapons?

The new slag is cool but it seems to me adding in "Frozen Weapons" that slow down enemies and give a chance to cause frozen foes to explode on critical hits would have been fun and added to the game play. Anyone have any idea why they left Ice out?

On another note, I have a melee/utility Zero. What weapon or weapons do you think go best with this class? So far, I like elemental pistols and SMGs. SMGS just because its good crowd control then you can finish them off with a quick melee strike.